You're certain it has small yellow flowers? What time of year does it flower? Not recognising it currently...

Yes bamboo ,yellowish flowers if I remember (I keep hacking it back so lose the flowers).It shoots up into a two metre bush if I let it and it has thick wooden branches that sucker like mad .It retains that reddish cast to the leaves and it seems semi evergreen.

I was thinking looks a bit like sucker growth off rootstock left in the ground - seems a difficult place to dig and uncover what's beneath the ground, but if I'm right, you'd need to reveal and drill into, then apply SBK to the holes, to kill it off. Treatment to the leaves won't work.

Its impossible to uncover it Bamboo as it seems to be growing from under next doors greenhouse flags but I can at least attempt to get it from my side .I posted a pic for ID back in 2008 which showed the flower buds before they opened but again it wasn't very clear.Last year I just let it grow and gave up the battle but it spread so badly I'm back on with the war again.

I've added a couple more pictures as its just about to flower now Bamboo.

Can you let that flower come out so we can see what it looks like...

Yes .I'll leave it until it does ,they are quite a nondescript yellow,similar to the small hypericum.

It has the look of a cotoneaster ( no name) someone gave me ( in a pot, thankfully) Its only saving grace for me is the brilliant autumn colour when it goes a spectacular red. I've just gone out to look at mine and it really is very similar, especially in the creases of the new leaves.

I'll check that out Ojibway but it doesn't resemble any cotoneaster i've seen so far :-)

Wild Vibernum or wild Dogwood ? Edit...ive just googled both of those and it looks nothing like them.

I have one growing outside my front garden and im sure it was identified as a Dogwood.

My first thought was dogwood Andy but the stems dont colour and it doesn't have the usual creamy dogwood flowers.I'm puzzled .

Try Cotoneaster Lucidus. It may not be that, but it looks similar.

To me it looks like Euonymus (Spindle).

Just googled Ojibway ,the leaves look too shiny these are very soft leaves like a cornus or viburnum and hubby says it did lose it leaves in winter .
Fractal ,I've never seen fruit on it but that may mean nothing but can't find any mention of the yellow flowers:-)

It has the look and sound of Diervilla sessilifolia. It is a bit of a thug as it spreads by underground branches.

That would explain it, Owdboggy - its described as a 'thicket former' which means its a thug that spreads underground...

Well thats certainly the closest so far .Will wait until the flowers come out but it certainly does have runners .
Thank you all :-))

It certainly looks like Cornus, and spindle is very similar, but yellow flowers? It sounds as if repeated applications of a systemic weedkiller like glyphosate is as good a remedy as you're going to get, whatever it is, Susie.

Gattina, I think Owdboggy's ID is correct...

Well, whatever it is, it grows like mad in the hedgerows round here, and I don't want it!

I've tried endless applications of glyphosate Gattina ,hubby even used an entire gas canister trying to burn it and it just shot right back up :-)I've managed to get to some of the roots so i'm going to try the drilling and applying brushwood killer suggested .Many thanks.

Glyphosate will do sweet fanny adams, as you've realised Susie - it doesn't work on woody plants.